The Cosmology Large Angular Scale Surveyor (CLASS) project aims to make a unique measurement of the Cosmic Microwave Background (CMB) that will transform our understanding of the universe and fundamental physics. This measurement will leave a far-reaching impact on the scientific community, the next generation of scientists, and the public. As electromagnetic radiation, the CMB has both an intensity and a polarization: It is the polarization of the CMB that CLASS will use to map over 70% of the sky.

Discover CLASS

To know more about CLASS, explore the rest of our website and connect with us on Twitter if you have any questions or comments! Further information about the science and technology of CLASS can be found under Publications. To understand more about the project, visit our Science page and our Wikipedia page. For updates on our team, take a look at news articles by the Baltimore Sun, the Hub, and The JHU News-Letter. For a more technical overview of the project, see the latest CLASS summary paper.


We acknowledge the National Science Foundation Division of Astronomical Sciences for their support of CLASS under Grant Numbers 0959349, 1429236, 1636634, 1654494, 2034400, and 2109311. The CLASS project employs detector technology developed under several previous and ongoing NASA grants. Detector development work at JHU was funded by NASA cooperative agreement 80NSSC19M0005. Data analysis for CLASS is conducted using computational resources of Advanced Research Computing at Hopkins (ARCH). We further acknowledge the very generous support of Jim and Heather Murren (JHU A&S ’88), Matthew Polk (JHU A&S Physics BS ’71), David Nicholson, and Michael Bloomberg (JHU Engineering ’64). CLASS is located in the Parque Astronómico Atacama in northern Chile under the auspices of the Agencia Nacional de Investigación y Desarrollo (ANID).